The United States would welcome Bharatiya Janata Party (BJP) leader Narendra Modi if he wins the upcoming election, a US official said, in the clearest sign Washington will drop a travel ban on Modi imposed after 2002 Gujarat riots.

U.S. Assistant Secretary of State Nisha Biswal told a television interviewer that Washington was ready to do business with Modi, the front runner ahead of the April-May general election who is best placed to form a coalition government.

"I would just say that the United States has welcomed every leader of this vibrant democracy, and that a democratically elected leader of India will be a welcome partner," Biswal told a TV channel when asked if Narendra Modi, as prime minister, would be granted a U.S. visa.

Biswal made her comments in New Delhi on a visit to rebuild trade and political ties shaken by a row over the arrest in New York last December of an Indian diplomat suspected of visa fraud.

U.S. Ambassador to India Nancy Powell visited Narendra Modi at his home in Gandhinagar last month, ending a long estrangement over riots that erupted in the state governed by the Hindu nationalist leader.

At least 1,000 people, most of them Muslims, were killed in 2002 when mobs went on a rampage across Gujarat after a train carrying Hindu pilgrims was torched, killing 59 people.

Powell's visit was the highest-profile encounter between U.S. officials and Modi since the State Department revoked his visa in 2005 over the bloodshed to which rights activists say he turned a blind eye. He denies the allegation.

Biswal said the United States hoped India would continue to build a tolerant, moderate and secular society when asked if Washington had put its human rights concerns on the back burner because of Modi's political rise.

"Visa issues are handled on a case by case basis. And determinations are made based on the facts of the day and are reviewed at the time that a request is made," she said according to a transcript released by the U.S. embassy.

The U.S. administration, which does not want to be seen as taking sides in the Indian election campaign, has stopped short of stating publicly that Modi would be able to travel to the United States should he win the lower house election, leading to speculation that he would not be welcome in Washington.

But diplomats say the until the election results are known, the question of whether Modi would